<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        /*子孙后代选择器*/
        /*body div div p{
            color: red;
        }*/
        /*子元素选择器*/
        body > p {
            color: red;
        }
    </style>
</head>
<body>
<p>p1</p>
<div><p>p2</p></div>
<div>
    <div><p>p3</p></div>
    <div>
        <div><p>p4</p></div>
    </div>
</div>
</body>
</html>